Windshield wiper mechanism

ABSTRACT

A stationary pin is mounted on a motor vehicle adjacent the windshield thereof. A sleeve is journaled for turning movement on the pin and has limited freedom of axial displacement relative to the same. A pair of arms project from this sleeve at opposite radial sides. A windshield wiper assembly is mounted on one of the arms and biassed into engagement with the windshield. Drive means is coupled with the second arm for imparting to the same and thereby to the sleeve an oscillatory movement about the pin which, at the will of an operator, may be varied from effecting displacement of the wiper assembly between two operating positions to effecting displacement of the wiper assembly from one of the operating positions to a rest position. Guide means in form of cooperating cam and follower means is provided for imparting to the sleeve in automatic response to movement of the assembly to its rest position, an axial movement with reference to the pin in a sense exerting upon the wiper assembly a second biassing force counter to the first biassing force so that the same is either partially negated or completely negated, with the wiper assembly in the latter case being lifted off the windshield.

United States Patent [72] lnventor Hubert Mainka Buhlertal, Germany [21]Appl. No. 29,374

[221 Filed Apr. 8, 1970 [45] Patented Sept. 14,1971

[73] Assignee Robert Bosch Gmbl-l Stuttgart, Germany [32] Priority Apr.15, 1969 [33] Germany [54] WINDSHIELD WIPER MECHANISM 10 Claims, 3Drawing Figs.

Primary Examiner-Peter Feldman Atl0rneyMichael S. Striker ABSTRACT: Astationary pin is mounted on a motor vehicle adjacent the windshieldthereof. A sleeve is journaled for turning movement on the pin and haslimited freedom of axial displacement relative to the same. A pair ofarms project from this sleeve at opposite radial sides. A windshieldwiper assembly is mounted on one of the arms and biassed into engagementwith the windshield. Drive means is coupled with the second arm forimparting to the same and thereby to the sleeve an oscillatory movementabout the pin which, at the will of an operator, may be varied fromeffecting displacement of the wiper assembly between two operatingpositions to effecting displacement of the wiper assembly from one ofthe operating positions to a rest position. Guide means in form ofcooperating cam and follower means is provided for imparting to thesleeve in automatic response to movement of the assembly to its restposition, an axial movement with reference to the pin in a senseexerting upon the wiper assembly a second biassing force counter to thefirst biassing force so that the same is either partially negated orcompletely negated, with the wiper assembly in the latter case beinglifted off the windshield.

WINDSI-IIELD WIPER MECHANISM BACKGROUND OF THE INVENTION The presentinvention relates generally to windshield wiper mechanisms, and moreparticularly to windshield wiper mechanisms for vehicles, especially formotor vehicles.

Known windshield wipers perform an oscillatory movement with referenceto a windshield, in the sense that they are displaced between twoangularly spaced working or terminal positions, and are further capableof movement to a rest position which is located beyond one of theworking positions and in which the wiper assembly is positioned outsidethe field of vision which is traversed by the assembly when it movesbetween its operating positions. To assure proper cleaning of thewindshield and removal of all contaminants, liquid, etc. therefrom, thewindshield wiper assembly is biassed into engagement with thewindshield. The wiper blade itself, however, consists of rubber or asuitable synthetic plastic substitute, and over a period of time theconstant biassed engagement of the blade with the windshield causes adeterioration of the characteristics of the wiper blade material, andtherefore in the effectiveness of the wiping action performed by theblade. It is therefore known to provide an inclined surface or cam facewhich cooperates with the arm on which the wiper blade is mounted insuch a manner that, when the arm and thereby the blade moves to rest orparking position, the blade is lifted off the windshield so as to befree from stress while the wipers are not in use. It has been found,however, that in many instances space limitations make it impossible toprovide such an inclined cam face, or else force the provision of thecam face at a location of the vehicle which possesses unacceptableproblems, either from a point of view of aesthetics or else withreference to operational considerations, for instance if the location issuch that in winter a freezing of the windshield wiper arm to the camface must be feared.

SUMMARY OF THE INVENTION It is, accordingly, an object of the presentinvention to overcome the aforementioned problems.

More particularly it is an object of the present invention to provide animproved windshield wiper mechanism which is not possessed of theseproblems.

Still more specifically, it is an object of the present invention toprovide an improved windshield wiper mechanism which affords in a mostsimple manner either a reduction in the force with which the bladeengages the windshield, or a complete lifting-off of the blade from thewindshield in automatic response to movement of the wiper assembly torest or parking position.

In pursuance of the above objects, and others which will become apparenthereafter, one feature of the invention resides in a windshield wipermechanism, particularly for use in motor vehicles, which briefly statedcomprises a support and a stationary pin mounted on this support. Asleeve is journaled for turning movement on the pin and has limitedfreedom of axial displacement relative to the same. A first arm projectsfrom the sleeve at one radial side and a second arm projects from thesleeve at another radial side. A wiper assembly is mounted on the firstarm under the influence of a first biassing force tending to move itinto engagement with a proximal windshield. Drive means is coupled withthe second arm for imparting to the same and thereby the sleeve anoscillatory movement about the pin in a sense effecting displacement ofthe wiper assembly between two operating positions, and at the will ofan operator effecting displacement of the wiper assembly from one of theoperating positions to a rest position. Finally, I provide guide meansoperative for imparting to the sleeve in automatic response todisplacement of the assembly to the aforementioned rest position, anaxial movement relative to the pin in a sense exerting upon the wiperassembly a second biassing force which is counter to the first biassingforce. This second biassing force may negate the first biassing forcepartially or completely, and in the former case the blade of the wiperassembly will engage the windshield with reduced force, whereas in thesecond case the blade will be lifted off the windshield in its entirety.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a partly section side view ofa windshield wiper mechanism according to one embodiment of the presentinvention, installed in a vehicle;

FIG. 2 is a section taken on the line lI-Il of FIG. 1; and

FIG. 3 is a fragmentary detail view analogous to FIG. 1, butillustrating a further embodiment of the invention in partial section.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing now the drawing indetail, and firstly'the embodiment in FIGS. 1 and 2, it will be seenthat reference numeral 10 identifies a windshield of a vehicle, forinstance-but not necessarilya motor vehicle. The windshield is mountedon a support 11, and reference character S identifies a somewhatdiagrammatically illustrated seal which prevents the entry of air andrain at the juncture between the windshield l0 and the support 1 I. Thesupport 11 may, of course, be a portion of the body of a motor vehicleor the like.

In any case, the support 11 is reinforced by a traverse I2 which is ofsubstantially U-shaped cross-sectional configuration. A pin 13 ismounted on the traverse l2 and journaled for turning movement on the pin13 is a sleeve 14. The latter also has limited freedom of axialdisplacement with reference to the pin 13, and adjacent the free end ofthe latter there is provided a conventional circlip or spring ring 15against which the sleeve 14 will eventually abut when it moves axiallyof the pin 13, so that its freedom of axial displacement is limited bythe circlip l5.

As FIG. 1 shows, two arms project from the sleeve 14 at different radialsides thereof. These arms may be rigid with the sleeves 14 or they maybe of one piece therewith, as illustrated in FIG. 1. One of the arms isidentified with reference numeral 16 and it carries at or adjacent itsfree end a ball pivot 17 by means of which it is connectable with a rodwhich is in turn connected with a motor crank of a drive. The drive andthe connection thereof with the ball pivot 17 are diagrammaticallysuggested by the dotted lines because such connection is well known tothose skilled in the art, as is the type of drive in question. It willbe appreciated that the circular movement of the motor crank of thedrive is converted into an oscillatory movement of arm 16 and sleeve 14about the pivot pin 13. It is further known to those skilled in the art,and will therefore not be separately discussed because it does not initself constitute a part of the present invention, how movement of thesleeve 14 in a sense effecting displacement of the windshield wiperassembly 30 to rest positionrather than displacement between the two endpositions located at opposite sides of the wiping fieldis effected. Inany case, it is briefly pointed out that when the drive is deactivated,the wiping assembly moves beyond one of the end positions out of thewiping field to a rest or parking position where it remains until thedrive is again activated.

A second arm 19 is of one piece with the sleeve 14 also, which projectsfrom the latter at a side opposite that from which the arm 16 projects.The arm 19 is a part of a wiper arm 19 composed of the arm 19, aconnecting portion 20 which advantageously consists of formed sheetmetal, and an elongated straight rod 21. The cross-sectionalconfiguration of the connecting portion 20 is U-shaped, in known manner.lts two lateral arms 22 embrace the arm 19 with small play. The portion20 and the rod 21, which is connected to it by means of rivets or thelike, are mounted on the arm 19 turnable about a bolt or pin 23. Afurther bolt or pin 25 traverses a recess 24 provided in the arm 19, andone end of a tension spring 26 engages the bolt or pin 25 whereas theother end of the spring 26 engages a projection 27 of the rod 21.Secured to the free end of the arm 18, that is more specifically to thefree end of the rod 21, is a wiper assembly 30 which is pivotable abouta pivot 21a. In known manner the assembly 30 is composed of a supportmember 31, two intermediate members 32 and a wiper blade 34 which isreinforced with one or more springy elements 33of spring steel or thelike-with the blade 34 being composed of rubber or a suitable syntheticplastic material. The spring 26 tends to displace the arm 18 withreference to the arm 19in clockwise direction, thereby urging the blade34 into abutment with the windshield 10. A nose 36 on the arm 19 is sopositioned that it will not normally come into contact with thetransverse wall 36 of the portion 20 as long as the assembly 30 is inoperating position in which it wipes the windshield 10.

In accordance with the present invention, and more particularly theembodiment illustrated in FIGS. 1 and 2, there are provided two guiderails 38 and 39 which extend in parallelism with one another as evidentfrom FIG. 2, and which are formed on the arm 16. Together with a planarportion 40 of the arm 16 these rails define a channel-shaped cam track41 for a roller 42 which is turnably mounted on a bracket 43 for turningmovement about an axis of rotation normal to the axis of the pin 13. Thebracket 43 is mounted releasably on the support 11 by means of suitableconnecting means, such as for instance a nut and bolt assembly 43a.

As FIG. 2 shows particularly clearly, the diameter of the roller 42 issomewhat smaller that the width b of the cam track 41 so that the rollercan turn freely when the arm 16 and the sleeve 14 oscillate in responseto having motion transmitted to them from the drive. One end of the camtrack 41 (compare FIG. 2) is offset by a distance c towards the support11.

When the drive is energized and the arm 16 and sleeve 14 oscillate aboutthe pin 13 in the sense causing displacement of the assembly 30 betweenits two operative positions, the cam track 41 moves with reference tothe roller 42, but the latter does not enter into the offset portionwhich is illustrated in FIG. 2. Thus, the spring 26 urges the blade 34into wiping engagement with the windshield 10.

When the drive is deactivated, the sleeve 14 is caused in conventionaland therefore nonillustrated manner to turn about the pin 13 beyond itsnormal angular displacementthat is beyond the displacement range whichit traverses while the drive is in operation and the wiper assembly 30wipes the windshield lso that the assembly 30 moves to a rest or parkingposition in which the assembly 30 is located outside the wiping fieldwhich is normally traversed when the wiper is in motion. As thismovement of the assembly 30 to its rest position takes place, thelaterally offset portion of the cam track 41 (compare FIG. 2) is sodisplaced with respect to the roller 42 that the latter enters into thisoffset portion and, because the axis about which the roller 42 rotatesis stationary, the cam track 41 and of course thereby the arm 16 and thesleeve 14 are caused to become displaced towards the lefthand side inFIGS. 1 and 2, so that the sleeve 14 moves away from the windshield 10.Initially, this displacement does not cause lifting of the blade 34 offthe windshield because the spring 26 compensates for such displacementin that it continues to urge the arm 18 to pivot about the pivot pin 23towards the right and to thereby maintain engagement of the blade 34with the windshield 10. However, and this takes place in the last thirdof the axial displacement of the sleeve 14 with reference to the pin 13,the transverse wall 35 of the portion will finally abut against the nose36 of the arm 19, preventing further displacement of the arm 18 aboutthe pivot 23 towards the right in FIG. 1, so that during continued leftmovement of the sleeve 14 with reference to the pin 13 until the sleeve14 engages the circlet 15, the blade 34 is lifted off the windshield 10.In this position the assembly 30 remains while the windshield wipermechanism is not in use. Of course, when the drive is energized and thewindshield wiper mechanism is intended to be used, then the reversetakes place.

In the embodiment of FIG. 3 the roller 42 is mounted on the arm 16,which is fast with or of one piece with the sleeve M. The cam track inthis embodiment is constituted by a sheet metal cam 44 which is securedto the support 11 and configurated correspondingly as required, that isanalogously to what has been shown in FIG. 2. A helical spring surroundsthe pin 13 intermediate the circlip 47 or other abutment provided inplace of the circlip, and the free axial end of the sleeve 14, urgingthe same towards the right and thereby urging the roller 42 intoengagement with the cam track 45.

It will be appreciated that among the various modifications which can bemade in the illustrated embodiments without departing from the scope andintent of the present invention, there is the possibility of having thebiassing force exerted by leftward movement of the sleeve 14 (seeFIG. 1) with reference to the pin 13 be such that it is not sufficientto lift the blade 34 entirely off the windshield 10, but only tocounteract to a desired extent the biassing force of the spring 26, sothat the blade 34 would still engage the windshield 10 but with reducedforce. It is also possible to so construct the cam tracks that theyimpart to the sleeve 14 an axial displacement with reference to the pin13 which is smaller than the one imparted when the assembly 30 moves torest position, but which takes place while the assembly 30 actuallyoperates and is being displaced between its two operating positions.This embodiment could be advantageous if the windshield 10 isparticularly strongly curved.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofconstructions differing from the types described above.

While the invention has been illustrated and described as embodied in awindshield wiper mechanism, it is not intended to be limited to thedetails shown, since various modifications and structural changes may bemade without departing in any way from the spirit of the presentinvention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims.

I claim:

1. A windshield wiper mechanism, particularly for use in motor vehicles,comprising a support; a stationary pin mounted on said support; a sleevejoumaled for turning movement on said pin and having limited freedom ofaxial displacement relative to the same; a first arm projecting fromsaid sleeve at one radial side and a second arm projecting from saidsleeve at another radial side; a wiper assembly mounted on said firstarm under the influence of a first biassing force tending to move itinto engagement with a proximal windshield; drive means coupled withsaid second arm for imparting to the same and thereby said sleeve anoscillatory movement about said pin in a sense effecting displacement ofsaid wiper assembly between two operating positions, and at the will ofan operator from one of said operating positions to a rest position; andguide means operative for imparting to said sleeve in automatic responseto displacement of said assembly to said rest position, an axialmovement relative to said pin in a sense exerting upon said wiperassembly a second biassing force counter to said first biassing force.

2. A mechanism as defined in claim 1, said guide means I comprising cammeans and cam follower means one of which is provided on said supportand the other of which is provided on said second arm.

3. A mechanism as defined in claim 2, said cam means being provided onsaid second arm, and said cam follower means being provided on saidsupport.

4. A mechanism as defined in claim 3, said cam means comprising anelongated cam track provided on said second arm, and said cam followermeans comprising a roller cooperating with said cam track and mounted onsaid support for turning movement about an axis transverse to theelongation of said cam track.

5. A mechanism as defined in claim 1; further comprising biassing meansengaging said wiper assembly and exerting upon the same said firstbiassing force.

6. A mechanism as defined in claim 2, said cam means comprising a camtrack provided on said support and being elongated in direction normalto the axis of said pin, and said cam follower means comprising a rollermounted on said second arm for turning movement about a rolling axisnormal to the axis of said pin and to the elongation of said cam track.

7. A mechanism as defined in claim 6; further comprising a biassingspring engaging said sleeve and tending to displace the same axially ofsaid pin in a sense effecting engagement of said roller with said camtrack.

8. A mechanism as defined in claim 4, said cam track being in form of achannel having an open side through which said roller extends into saidchannel.

9. A mechanism as defined in claim 4, said cam track having a firsttrack portion along which said roller moves during displacement of saidwiper assembly between said operating positions, and a second trackportion offset with reference to said first track portion and intoengagement with which said roller moves in response to displacement ofsaid wiper assembly to said rest position.

10. A mechanism as defined in claim 7, said pin having an axial lengthgreater than that of said sleeve and being provided with a free end;further comprising a circlip encircling and connected with said freeend; and wherein said biassing spring is helical and surrounds said pinintermediate said circlip and said sleeve bearing against both withopposite ends.

1. A windshield wiper mechanism, particularly for use in motor vehicles, comprising a support; a stationary pin mounted on said support; a sleeve journaled for turning movement on said pin and having limited freedom of axial displacement relative to the same; a first arm projecting from said sleeve at one radial side and a second arm projecting from said sleeve at another radial side; a wiper assembly mounted on said first arm under the influence of a first biassing force tending to move it into engagement with a proximal windshield; drive means coupled with said second arm for imparting to the same and thereby said sleeve an oscillatory movement about said pin in a sense effecting displacement of said wiper assembly between two operating positions, and at the will of an operator from one of said operating positions to a rest position; and guide means operative for imparting to said sleeve in automatic response to displacement of said assembly to said rest position, an axial movement relative to said pin in a sense exerting upon said wiper assembly a second biassing force counter to said first biassing force.
 2. A mechanism as defined in claim 1, said guide means comprising cam means and cam follower means one of which is provided on said support and the other of which is provided on said second arm.
 3. A mechanism as defined in claim 2, said cam means being provided on said second arm, and said cam follower means being provided on said support.
 4. A mechanism as defined in claim 3, said cam means comprising an elongated cam track provided on said second arm, and said cam follower means comprising a roller cooperating with said cam track and mounted on said support for turning movement about an axis transverse to the elongation of said cam track.
 5. A mechanism as defined in claim 1; further comprising biassing means engaging said wiper assembly and exerting upon the same said first biassing force.
 6. A mechanism as defined in claim 2, said cam means comprising a cam track provided on said support and being elongated in direction normal to the axis of said pin, and said cam follower means comprising a roller mounted on said second arm for turning movement about a rolling axis normal to the axis of said pin and to the elongation of said cam track.
 7. A mechanism as defined in claim 6; further comprising a biassing spring engaging said sleeve and tending to displace the same axially of said pin in a sense effecting engagement of said roller with said cam track.
 8. A mechanism as defined in claim 4, said cam track being in form of a channel having an open side through which said roller extends into said chanNel.
 9. A mechanism as defined in claim 4, said cam track having a first track portion along which said roller moves during displacement of said wiper assembly between said operating positions, and a second track portion offset with reference to said first track portion and into engagement with which said roller moves in response to displacement of said wiper assembly to said rest position.
 10. A mechanism as defined in claim 7, said pin having an axial length greater than that of said sleeve and being provided with a free end; further comprising a circlip encircling and connected with said free end; and wherein said biassing spring is helical and surrounds said pin intermediate said circlip and said sleeve bearing against both with opposite ends. 